When is a file moved from the Data area to Retention?
A file is moved from Data area to Retention area of [DataLock Server] when it is modified or removed on the source machine.

How long will the file(s) be kept in the Retention?
Retention policies define what files in Retention area should be kept, retained files no longer covered by the Retention policy will be deleted from Retention area and the corresponding file versions will no longer be recoverable. In other words, a 7 day, 5 week, 13 month, 5 year policy does not mean creating 30 copies of the backup data.

Can you tell us more on how Retention Policy works?
Assume the following retention policy is set: 7 day, 5 week, 13 month, 5 year retention policy

• A file that has not been changed for 5 years will remain in Data area and no copies will be made
• A file modified once in the 2nd year will have the current version stored in Data area and the previous version in Retention area after 5 years
• A file created and removed within a year, for example, it never exists in Data area during any of the year end jobs, thus is not covered by the 5 year policy, will be removed within 13 months, depending on how file is being covered by the monthly policy
• When performing a file backup, only new or modified files will be backed up. In other words, even if you set a full file backup to be run on a particular day, it will only pickup files that have deltas and are modified since the last backup.

What about the "Remove retention files for overlap policy" option? Can you give us more details on this option?
The "Remove retention files for overlap policy" option could be used if the user wants to further reduce the amount of required storage while complying with his backup policies. Let's look at an example here:

For instance, a company requires backups of its sales database at the end of each month, and once they got this month-end backup, those daily backups for that month would become redundant. i.e. Once they got the 30th Jun backup, all 29th Jun, 27th Jun, ... 1st Jun backups are not longer needed. In this case, they could set a Daily retention policy of 31 days, plus a Monthly policy for the end of each month, and then enable the "Remove retention files for overlap policy" option. This would effectively remove the files retained by daily backups proceeding the end of month backup.

Are there any recommendation on how the retention policy should be set?
We would suggest that the retention policy set should be longer that the typical frequency of use for the files in the backup source. In other words, if a particular set of file is only used once quarterly, then the backup data should be retained for more than a quarter.